Generator head for fuel-oil burners



Sept. 30, 1924. 1,510,093

S. H. LESH GENERATOR HEAD FOR FUEL OIL BURNERS Filed Nov. 20. 1923 5/1 LES/1. mmvToRf V A TTORNEE Patented Sept. 30, 1924.

UNITED STATES SAMUEL H. LESH, 0F LINCOLN, NEBRASKA.

GENERATOR HEAD FDR FUEL-OIL BURNERS.

Application filed November 20, 1923.

To all whom it may concern:

Be it known that I. SAMUEL H. LnsH, a citizen of the United States, residing at Lincoln, in the county of Lancaster and State of Nebraska, have invented certain new and useful Improvements in Generator Heads for Fuel-Oil Burners, of which the following is a specification.

. y invention relates to a generator head for fuel oil burners.

One of the commonest and best known forms of fuel oil burners consists of two metallic plates which are dome or cone shaped and which are so constructed that one of th plates may be positioned above the other separated by a narrow space. The lower of these two plates is the generator head for the burner. It is convex on its upper side and the oil being fed to the central or highest point of the upper surface of the generator head flows toward the periphery thereof. The upper plate is con cave on its under surface and in the opera tion of the burner this plate is kept heated. Its function is to vaporize the oil as it flows down the upper surface of the generator head, to confine the oil vapor under pressure until it reaches the outlet at the periphery and to ignite the oil vaporas it emerges. The lower plate or generator head. is normally kept at a lowcrtemperature by the cooler air which is drawn in under the generator head to be mixed with the oil vapor at the time of ignition, since it has been found that excessive heat in the lower plate causes imperfect combustion and the accumulation of carbon.

Carbon in the form of soot may however result from other causes. If the oil flows too rapidly toward the periphery of the burner, or if it fails to spread evenly over the generator head, carbon will result with all of the attendant annoyance and waste of fuel. To obtain and maintain the extreme accuracy in the level. of the generator head required for the even flow of oil has been the most difficult factor in the installation of oil burners.

The object of my invention is the pro vision of a generator head in which the oil will be caused to spread out immediately in the form of thin films, to cause these thin films of oil to flow slowly and throughlong passages toward the peripheral outlets to be completely vaporized in the passages. to

eliminate the necessity of extreme precision Serial No. 675,887.

in the levelling of the burner, and to cause the oil vapor to issue in the form of jets under considerable pressure. Thes objects and others will be explained in greater detail in the description.

Referring now to the drawings which are part of my application,

Figure l is a plan view of a generator head embodying my improvements.

Figure 2 is a median vertical section of the entir burner, A being the generator heath B the cap and C the bowl.

As shown, the generator head has a rounded or dome shaped upper surface. While I prefer the construction as shown it is obvious that the same principles can be carried out in any generator head having a raised central part and gradual downward slope in all directions toward the periphery.

The generator head is provided with a central passage 10 through which the fuel oil is fed to the upper surface of the generator head. Referring now to Figure 1, there are several passages or channels 11 for breaking up the stream of oil which emerges from the opening of the passage 10 and for conducting the smaller streams radially andin a substantially horizontal direction.

The upper surface of the generator head is also provided with spiral ribs 12, the number being equal t the number of the channels 11, the ribs however being offset with relation to. the outlets of the channels. Each rib 12 terminates at its inner or upper end in an arcnate rib 13, the ribs 13 being concentric with the oil passage 10 and constituting in effect a broken circular rib. The spaces between the spiral ribs constitute elongated passages for the oil which enters in the gaps between the ribs 13. It should be here noted that these gaps are positioned oppositeand in line with the passages 11 so that the oil will enter directly into the passages between the spiral ribs. A certain amount of the oil will however 1m pinge on the inner walls of the arcuate ribs 13 where it will spread out and creep down-- wardly into'the channels between the spiral ribs. this tendency being somewhat vmore pronounced when the burner is working at or near its-maximum capacity.

While in the liquid or semi liquid state, the oil moves slowly doi'vnwaivl the tendency being .tomove along the concave walls of the spiral'ribs. In its downward movement it is always subjected to the heat from the upper plate or hood, thus becoming completely vaporized. In order to properly control the movement of the oil vapor l have found it necessary toadd several new features to the spiral ribs at their lower extremities The extreme lower end 1% of each spiral rib is sharply deflected into circular form concentric with the axis of the generator head. it 15 each circular rib is thickened. The combined effect of these two' constructions is to create a certain amount of pressure in the oil vapor and to deflect the movements of the oil vapor from their spiral toward circular paths, but the thickened portions 15 of the spiral ribs have a second and more important function. The deflected heat from the upper plate or hood heats the ribs, the thickened portions 15 receiving and retaining the greatest quantity of heat and thus facilitating the vaporization of the oil in the final stages.

An upwardly extending rib 16 surrounds the generator at its periphery, the rib 16 being provided with gaps or openings 17. It is important that the openings 17 be positioned as shown in Figure 1. The vapor as it is forced from the passages between the spiral ribs has consider able velocity and has been deflected toward but not into a circular path. It thus strikes the inner wall of the rib 16, its tendency being to assume a vortex motion in a circular direction with the lighter vapors next to the wall of the rib 16. The heavier portions of the vaporized oil are away from the rib 16 and whirling in close contact with the thickened portions 15 of the spiral ribs. The lighter vapors are forced out under pressure through the openings 17 but the heavier portions travel in a circular di rection in the zone of greatest heat and thus completely vaporized before they are permitted to reach the openings 17. Upon leaving through the openings 17, the oil vapors are mixed with air and are ignited. forming spiral jets of flame around the periphery of the generator head. These jets of flame combine to form a solid whirling sheet of flame which is forcibly directed against the furnace wall.

The provision of spiral grooves or passages very materially lengthens the journey that the oil must make toward the periphery of the burner. this being more than four times the radial distance in the structure shownin my drawings. This reduces the pitch of the groove, and in consequence the oil moves at a very slow rate through a considerable distance, being at all times subjected to the heat of the spiral ribs. The oil thus becomes completely vaporized n its passage so that in the normal operation of the burner no liquid or partially vaporized oil can reach the outlets of the spiral passages, even though the burner may be somewhat off the true level. The oil will be more evenly distributed in the spiral pussages than it would be in off level burners of other kinds. A slight unevenness in dis tribution in the oil would however occasion no trouble in the spiral passages since nothing but oil vapor can reach the outlets of the passages, and oil vapor tends toward an even distribution at the periphery where as liquid oil does not- This tendency is however increased by the whirling motion which is given to the oil vapor when it emerges from the passages.

Having thus described my invention in terms which will be readily understood by others skilled in the art to which it pertains, what 1 oelieve to be new and desire to secure by Letters Patent of the United States is 2- 1. In an oil burner of the kind comprising a generator head and a hood therefor and wherein the upper surface of the generator head is convex, means being provided for delivering fuel oil to the generator head at its topmost point. spirally arranged ribs on the upper surface of the generator head. said ribs having passages thcrebctween for conveying the fuel oil toward the periphery of the generator head. said ribs being also so formed as to restrict both. the inlets and the outlets of the oil passages.

2. In an oil burner of the kind comprising a generator head having a convex upper surface with means for delivering fuel oil to the topmost point thereof and a hood for heating and vaporizing the oil on the generator head, a plurality of spirally arranged ribs projecting upwardly from the generator head. said ribs serving as the lat eral walls of spiral passages for receiving the oil at the top of the generator head and for conveying it toward the periphery f the generator head and serving also to re ceive the heat from the hood and to there-- by heat and vaporize the oil, in its passage, said ribs being widest at or near their lower or outer extremities. said widened portions serving to subject the oil to the maximum temperature as it leaves the passages.

3. A generator head for fuel oil burners, said generator head being convex on its upper surface and having a circular periphery, means for delivering fuel oil to the upper surface of said generator head at the central point thereof. a plurality of upwardly projecting arcuate ribs surrounding the central point of said generator head. and a plurality of upwardly projecting spirally arranged ribs, each of said spirally arranged ribs extending downwardly from an arcuate rib to a point spaced from but in proximity to the periphery of the generator head.

4. A generator head for fuel oil burners,

said generator head having a circular periphcry and having its upper surface sloping downwardly in all directions from the center toward the periphery thereof, said generator head being provided with a central. vertical conduit with a discharge opening at the upper surface of the generator head whereby fuel oil may be delivered through the generator head-to the topmost point of the upper surface thereof, a plurality of arcuate ribs on the upper surface of said generator head, said arcuate ribs constituting a circular series of ribs surrounding the central discharge opening, each of said arcuate ribs having a spiral rib projecting therefrom on its convex side, said spiral ribs being on the upper surface of said generator head and extending downwardly toward the periphery thereof, each of said spiral ribs being deflected at its lower or outer end from the spiral form to restrict the outlets of the channels between adjacent spiral ribs.

5. A generator head for fuel oil burners, said generator head being convex on its upper surface and having a circular periphery, means for deliverying fuel oil to the upper surface of said generator head at the central. point thereof, means for conducting the fuel oil through elongated spiral channels from the center toward the periphery of said generator head, said means terminating short of the periphery of the generator head, and a plurality of upstanding arcuate ribs at the periphery of said generator head, said arcuate ribs having openings between each pair of arcuate ribs through which the vaporized fuel oil is dis charged.

6. Al generator head for fuel oil burners, said generator head being circular in outline and having an upper surface which slopes in all directions from its central point toward the periphery, a plurality of spiral ly arranged ribs on the upper surface of said generator head, said spirally arranged ribs terminating short ofboth the central point and of the periphery of the generator head, the spaces between the spirally arranged ribs being elongated spiral channels for conducting the oil and oil vapor toward the periphery of the generator head, a plurality of circularly arranged arcuate ribs at the periphery of said generator head, said arcuate ribs having openings therebetween to permit the escape of oil vapor from said generator head, the openings between the arcuate ribs being offset with respect to the outlets of the spiral channels.

7. A generator head for fuel oil burners comprising a plate whose upper surface slopes downwardly in all directions from its center, an oil feed passage for conducting fuel oil to the topmost point of said head, spiral ribs extending downwardly to form passages therebet-ween for the fuel oil, a circular rib surrounding said head at its periphery, said circular rib being provided with openings for the escape of oil vapors, and means on said spiral ribs for accelerating the rate of flow of the vapor as it leaves the passages between the spiral ribs.

In testimony whereof I ture SAMUEL H. LESH.

aflix my signa- 

